From resistance to treatment: the ongoing struggle with Acinetobacter baumannii

Acinetobacter baumannii (A. baumannii) has become a major hospital-acquired pathogen, well-known for its rapid development of resistance to multiple antibiotics. The rising incidence of antibiotic-resistant A. baumannii presents a significant global public health challenge. Gaining a deep understanding of the mechanisms behind this resistance is essential for creating effective treatment options. This comprehensive review explores the understanding of various antibiotic resistance mechanisms in A. baumannii. It covers intrinsic resistance, acquired resistance genes, efflux pumps, changes in outer membrane permeability, alterations in drug targets, biofilm formation, and horizontal gene transfer. Additionally, the review investigates the role of mobile genetic elements and the clinical implications of antibiotic resistance in A. baumannii infections. The insights provided may inform the development of new antimicrobial agents and the design of effective infection control strategies to curb the spread of multidrug-resistant (MDR) A. baumannii strains in healthcare environments. Unlike previous reviews, this study offers a more integrative perspective by also addressing the pathogen's environmental resilience, with particular emphasis on its resistance to desiccation and the formation of robust biofilms. It further evaluates both established and emerging therapeutic strategies, thereby expanding the current understanding of A. baumannii persistence and treatment.